Field
The present disclosure relates to telecommunications apparatus and methods.
Description of Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
The present disclosure relates to wireless telecommunications systems and methods.
Mobile communication systems have evolved over the past ten years or so from the GSM System (Global System for Mobile communications) to the 3G system and now include packet data communications as well as circuit switched communications. The third generation partnership project (3GPP) is developing a fourth generation mobile communication system referred to as Long Term Evolution (LTE) in which a core network part has been evolved to form a more simplified architecture based on a merging of components of earlier mobile radio network architectures and a radio access interface which is based on Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) on the uplink.
Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architectures, are able to support a more sophisticated range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems.
For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy third and fourth generation networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to increase rapidly.
The anticipated widespread deployment of third and fourth generation networks has led to the parallel development of a class of devices and applications which, rather than taking advantage of the high data rates available, instead take advantage of the robust radio interface and increasing ubiquity of the coverage area. Examples include so-called machine type communication (MTC) applications, some of which are in some respects typified by semi-autonomous or autonomous wireless communication devices (MTC devices) communicating small amounts of data on a relatively infrequent basis. Examples include so-called smart meters which, for example, are located in a customer's home and periodically transmit data back to a central MTC server relating to the customer's consumption of a utility such as gas, water, electricity and so on. Smart metering is merely one example of potential MTC device applications. Other examples include vehicle communications systems (for example, vehicle-to-vehicle (“V2V”), vehicle-to-pedestrian (“V2P”) or vehicle-to-infrastructure/network (“V2I/N”) systems, referred to generically as “V2X” arrangements. Further information on characteristics of MTC-type devices can be found, for example, in the corresponding standards, such as ETSI TS 122 368 V11.6.0 (2012-09)/3GPP TS 22.368 version 11.6.0 Release 11).
In MTC arrangements, including V2X systems, technical issues can arise in the provision (by a base station) or acquisition (by a terminal device) of so-called system information. In broad summary, system information, or at least some aspects of system information, in existing wireless telecommunications systems, such as LTE-based telecommunications systems, is transmitted as System Information Blocks (SIBs). Receipt of the SIBs is required in order for a terminal device to be able to communicate with a cell, for reduced capability devices such as MTC devices, these SIBs can be large in comparison to the data handling capabilities of the device. This can also be an issue in the context of vehicle-based devices, where the movement of the vehicle (and the potential small size of cells defined, for example, by road-side units (RSUs) means that the time spent by a terminal device in a particular cell may be short. Similarly, in the context of coverage enhancement, it is sometimes difficult for a terminal device (whether reduced capability or not) to receive large SIBs. There is therefore a need for schemes which allow system information to be communicated to terminal devices operating on restricted frequency resources in wireless telecommunications systems. There is also a need for schemes which allow system information to be communicated to terminal devices operating in a coverage enhancement situation.
It is a constant aim to improve the operation and efficiency of wireless network systems.